Tuesday, January 16, 2007

Perogies from Lisa's Test Kitchen!

I was inspired by the America's Test Kitchen approach from the Cook's Illustrated folks, which results in the full-disclosure style of "The New Best Recipe", and from there, my newly-reliable baking skills. So for my yearly Ukrainian 12-meatless-dishes feast, since I scaled down to making only perogies and kutya this year and my lovely friends brought the rest of the food, I decided to do some testing. Like Cook's Illustrated, I began by collecting a range of perogy dough recipes that differed significantly, and tried three of them. Here are the results of testing three different base recipes, with the main criteria being handling (rolling out dough and sealing the filling in side is hard to do properly with my mom's recipe) and tenderness.

1. Growing Alberta's recipe: in one of the many, MANY ways of combining just oil, flour, water, salt and eggs, this recipe is very simple and similar to many pasta recipes (e.g. ravioli dough). Most other perogy dough recipes I found online had the same basic ingredients in only slightly different quantities. Results: the dough itself is easy to make up, and then sufficiently easy to work. However, when boiled, this ended up making mutant-looking perogies: oddly lumpy, with a surface texture that looked a little more shiny and bubbly. The texture, more importantly, was a little more rubbery than ideal, and was not anybody's favourite in taste-testing.

2. Epicurean's recipe: this had a cup of sour cream instead of any water, and it also adds some baking soda (the rest is flour, egg, salt). This seemed sufficiently different to be worth trying. Result: this made a fine dough that rolled out reasonably well and sealed well. This was the most robust and even dough: every single perogy made using this dough looked like a perfect, even, golden half-moon, even after boiling and frying. At least one person decided this also produced the best texture or tooth.

3. My usual recipe, from my mom, given to her by a Polish friend in Edmonton who was a fabulous cook. This dough is my standard to compare to because I've made it before: it's very tender and everybody loves it, but it's a pain to roll out and use for perogies as it's so fragile. There are usually a few casualties during boiling, where the dough opens and water gets inside the perogy even if the filling doesn't spill out. It's also unreliable: it uses 1/2 cup of mashed potatos, which is hard to standardize (varies by type of potato, size, how long boiled, how carefully mashed, and how long left to stand to accumulate or release moisture after boiling/mashing). I couldn't find any recipes on the Web that had mashed potato in the dough, so it appears to be a unique recipe. Taste-testing results: most people found this was the best texture.

Here's that "heirloom" recipe for comparison:

1 and 3/4 cup flour

2 egg yolks

1/2 cup mashed potatos

2 tablespoons shortening

1 teaspoon cream of tartar

1/2 cup warm water

1 teaspoon salt

Mix flour, cream of tartar and salt together. In separate bowl, mix mashed potatoes, egg yolks, shortening and water together. Now mix wet and dry ingredients together, adding flour as necessary for a workable dough [this always comes up too wet, I need to adjust that]. Let sit 10 minutes before rolling dough. Roll a portion of the dough to a couple millimeters thick. Cut circles [I use a water glass inverted]. Put a spoonful of filling on each circle. Fold over circle and seal with water.

The next step in this testing process appears to be to start varying the best recipe found so far, to see if its most important advantages can be improved, its drawbacks minimized, or its technique simplified. This is helped along by hypotheses about what makes this the best (or by what makes it difficult). These are the variations on my usual recipe that I've tried so far.

Try omitting the cream of tartar as its role is not apparent in the absence of egg whites. Result: the exact same dough made with and without cream of tartar had apparently the same texture, but turned quite grey while standing, as the potato starch interacted with air. The grey blotchy dough was so unappealing that I threw it out without attempting to roll it out, cook it, etc. Conclusion: keep using cream of tartar as long as the recipe contains potato.

Try using a beater on wet ingredients, both to save labour and to improve consistency and robustness of dough by making sure the potatos are well-mashed. My regular dough always has a few visible bits of potato once I roll it thin, and sometimes this creates a weak spot as I form or cook a perogy. Results: using the beater made the dough turn out too gluey and it stuck to everything, making the rolling/folding even harder than normal and without making the dough any more robust. This result could have been guessed if you knew not to over-mash potatoes.

If letting it sit 10 minutes is good, is letting it sit longer even better? I tried a couple variations here. Results: Overnight wasn't good (though the results may be conflated with having used a beater on that batch). I also didn't see any difference waiting 10 minutes or an hour when the recipe was otherwise done the same way.

That was enough experimenting for one person for one year. What are the promising avenues for testing next year?

Sometimes the Cook's Illustrated people form a hypothesis about what makes a recipe good, and try to achieve the same goodness with a different approach. My hypothesis here is that the point of adding mashed potato to the dough is probably to increase the amount of starch relative to the amount of gluten. This should make the dough a little less rubbery or more tender. This hypothesis suggests there might be a more reliable way of reducing gluten ratios than using mashed potatos -- for example, using more cake flour and less all-purpose flour. Thus, I should look into how to reduce gluten ratio without using mashed potatoes (or using less of them). How much all-purpose flour should be replaced with cake flour?

Try to simplify technique and increase reliability by using instant mashed potatos. This approach would not suffer from variability in the starch content or waxiness of the potatoes, or from changes in the details of cooking and mashing.

Try the sour cream dough again. It was definitely easier to work with and people were not unhappy with the result. I want a bit more direct comparison (with the exact same filling, side by side) and evaluation to be confident that this is as tender, or just about as tender, to see if it's worthwhile switching from my traditional recipe.

Combine the two most successful recipes: what about using the mashed potato recipe with sour cream instead of water?

Also, next year I need to take pictures. As I write this blog post two days later, it's too late: they're all gone. Very popular, I tell you. My guests take home leftovers if there are any (last year there weren't) although I insist they leave leftovers for me too.